It reads like a story ripped from crime show drama: A San Diego Police crime lab technician worked in the same lab where evidence from a 30-year-old homicide he's accused of committing was processed.
Criminalist Kevin Brown was a member of the SDPD lab team from 1982 to 2002, joining the department two years before homicide detectives there started investigating the death of 14-year-old Claire Hough in August 1984.
The teen was found brutally beaten and strangled on Torrey Pines Beach with one of her breasts cut off.
For decades, the case ran cold, but in 2012, the SDPD homicide unit got two matches for DNA found on Hough’s body. Police say they tied Brown and a second suspect, Ronald Tatro, to the crime.
But attorney Gretchen von Helms, who represented Brown, believes her client’s DNA showed up because of evidence cross-contamination at the lab.
SDPD Cpt. Al Guaderrama told NBC 7 that is not the case.
"There are several safeguards that are actually put in place in regard to cross-contamination and we do not believe that was an issue in this case at all,” said Guaderrama.
Those safeguards include tracking each and every lab technician that works on a case and requiring lab personnel to submit DNA samples before they are hired.
The police captain said Brown did not take part in Hough’s case but mainly processed evidence for firearms and narcotics crimes.
"We know for a fact he had nothing to do with the Claire Hough case, and this was obviously determined (because) we knew where he was working at the time and with several other lab personnel interviews that actually took place during this investigation,” said Guaderrama.
Neither suspect can give their side.
Tatro, who served prison time for trying to abduct another young girl, died in a boating accident in 2011.
Brown was found dead of an apparent suicide on Oct. 21 in Cuyamaca State Park, just before investigators were prepared to make an arrest in the case.
Von Helms told NBC 7 her client’s suicide should not be interpreted as guilt. Instead, it was a result of anxiety and deep depression brought on by this investigation, she said.
On Friday, von Helms revealed Brown had taken an independent polygraph test by a retired SDPD employee, and the results showed he was innocent, according to his attorney.
Guaderrama said he could not comment on those results at this time. However, he did respond to questions about the suspects’ possible tie to a similar case from 1978, when 15-year-old Barbara Nantais was found dead on the same beach as Hough, strangled and beaten to death with one of her breasts severed.
"What I can tell you at this time is there's nothing at this time to link these two suspects to that murder,” said Guaderrama.
Investigators are still looking into whether Brown or Tatro are tied to other crimes.